The compound 12-carboxy-10,11-dihydro-5,10-methano-5H-dibenzo[a,d]cycloheptene (I) is a known intermediate compound in a process for preparation of pharmacologically active 10,11-dihydro-12-(substituted aminoalkyl)-5,10-methano-5H-dibenzo[a,d]-cycloheptenes. (See U.S. patent application Ser. No. 194,056 or German Offenlegungschrift No. 2,216,884.) The novel route of this invention for preparing this valuable intermediate employs several novel intermediates.
References useful to show the state of the art include S. Wawzonek et al, J. Org. Chem. 18, 288 (1953); W. R. Vaughan et al, J. Am. Chem. Soc. 80, 1956 (1958); C.A. 61, 6971f, thesis of D. E. Plorde and C. A. 61, 14551, thesis of J. Mohrig.